Evaluating idiopathic venous thromboembolism: What is necessary, what is not

We would not recommend discontinuing anticoagulation to conduct testing for these uncommon defects once it has been initiated following an acute thrombotic event. Rather, testing should be pursued once the planned course of anticoagulation with warfarin has been completed (for example, 6 to 9 months).

Other inherited thrombophilic disorders include heparin cofactor II deficiency, plasminogen deficiency, dysfibrinogenemia, factor XII deficiency, and increased factor VIII coagulant activity. These disorders are rare and their clinical importance remains unclear. Testing for these disorders, if desired, is best conducted in consultation with a hematologist or coagulation specialist.

Corresponding author
Charles F.S. Locke, MD, Johns Hopkins Community Physicians, 2360 W. Joppa Rd., Baltimore, MD 21093. E-mail: clocke@jhmi.edu.